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<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // 赋值
        var a = 10;
        a += 5;  // 相当于a = a + 5
        console.log(a);
        
        a = 10;
        a -= 5;  // 相当于a = a - 5
        console.log(a);

        a = 10;
        a *= 5;  // 相当于a = a * 5
        console.log(a);

        a = 10;
        a /= 5;  // 相当于a = a / 5
        console.log(a);

        a = 10;
        a %= 5;  // 相当于a = a % 5
        console.log(a);

        a = 10;
        // 相当于 a = a; a=a+1;
        console.log(a++);

        a = 10;
        console.log(++a);

        a = 10;
        // 相当于 a = a; a = a - 1
        console.log(a--);

        a = 10;
        console.log(--a);
    </script>
</body>
</html>